Heavy snowfall in Istanbul paralysed traffic for a third straight day Monday with the Bosphorus closed to shipping traffic and hundreds of flights cancelled again.  

With freezing temperatures and heavy winds, the Bosphorus, one of the world's busiest shipping bottlenecks, was closed due to poor visibility, Turkish coastguards said. 

All passenger ferry services, popular with commuters between the Asian and European side of Turkey's largest city, were also cancelled.

Schools were shut across the city, Istanbul's governor Vaship Sahin said on his Twitter account. 

In the worst snowfall since 2015, hundreds of flights have been cancelled over the last three days, stranding thousands of international passengers in Istanbul. 

Flag carrier Turkish Airlines (THY) said only 292 departures from Ataturk Airport expected Monday.

On a normal day, the airport can accommodate over 1,500 landings and take-offs.

Turkish Airlines CEO Bilal Eksi said on Twitter that only 171 flights had operated on Sunday and over 600 flights had been cancelled, prompting angry complaints from stranded travellers.

The problems were due to a lack of take-off and landing slots at Ataturk in the snowy conditions, he said. 

Over 10,000 travellers unable to reach Istanbul had been accommodated in hotels worldwide while well over 5,000 who could not leave were put up in the city, Eksi said. 

The Istanbul municipality meanwhile sent over 1,300 vehicles and 7,000 personnel into the streets to clear the snow.

The city's metro and tram systems worked round the clock to make up for the problems on the roads on Sunday.